I know theres a ton of threads already on this subject (I've read a lot of them), but a few seemed to contradict each other and I'm a nub when it comes to this stuff so I figured I'd post this to get some finite answers. I bought a Hartke HA5500 head and am about to buy two Hartke Hydrve 112s. As far as my I understand (correct me if I'm wrong): if I switch both the cabs to 8ohms and run them in parallel then I will get a 4ohm output of 500w from the amp, the capability of the amps at 8ohms is 300w each so I would be using 500/600w of possible power when running them parallel, if I plug into a single cab with the amp at 8ohm I would be outputting 350w which is 50w above the capability of the cab (which can cause damage?). So if my understanding of everything is messed up somewhere, please tell me. I'm trying to figure out if I should keep the amp or downgrade to the HA3500 as not to overpower the cabs when running them individually.
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Question on amp wattage and ohms
- Thread starter ryanleh.ob
- Start date
The two CABS would have a possible input power of 600 watts. Yes, at 8 ohms you could exceed the input power of one cab so use your ears and turn down if the speaker starts complaining. The amp will only output the power you ask it to up to it's rated output.
Ok, so individually I wouldn't damage the cab unless I cranked up the volume a ton, but using them in parallel I'll be totally fine if I crank it up? The way people described plugging an amp into a lower wattage cab made it sound like I would damage immediately without even playing.
I'm not saying in parallel you couldn't damage the cabs. But in either case yes, you have control over how much power is outputted. Amps put out zero watts with no signal no matter how "big" they are unless they are broken. An octave pedal might blow either combo at "seemingly moderate" volume levels without proper care of use. Mid scoop as an example lowers the volume of sounds we are most sensitive to (the mids) while huge power might slam the speakers at very low frequencies
Ok awesome!
For running parallel: Without using effects would it possible to damage the cab even if you cranked it? Wouldn't you, even then, be under its max capability?
There "can" be a real difference on what a speaker can handle before damage at low frequencies as opposed to what an average expectation is. No standard really exists especially for bass or PA sub use. Paying attention to the numbers only will help with a warranty claim, after that you are the best control over the length of service they will have.
Long answer, short yes it may still be possible. You are one with the hands on, with care most experience no problems in their lifetimes.
To be bulletproof you'd generally run cabs rated at twice the amp - for instance my backline amp is 350w into a 600w cab. Less cab than that I'd certainly not let anyone else play through it - and with just myself paying through it, I'd wonder how lucky I felt that day 
. But it's your stuff so "smoke 'em if yah got 'em" .
. But it's your stuff so "smoke 'em if yah got 'em" .
What B string said.
All the numbers in the world mean exactly zero. Forget them. They are marketing. They mean virtually nothing in the real world.
Watts aren't "the same no matter what". There is a huge difference between 30W behind guitar frequencies into two 4-12 Marshall cabs and 30W behind a low F# on bass into a 1-12 Hydrive cab. Those two scenarios bare almost no resemblance. So forget watts.
Listen to the speakers. They will shown signs of distress if you push them too hard.
All the numbers in the world mean exactly zero. Forget them. They are marketing. They mean virtually nothing in the real world.
Watts aren't "the same no matter what". There is a huge difference between 30W behind guitar frequencies into two 4-12 Marshall cabs and 30W behind a low F# on bass into a 1-12 Hydrive cab. Those two scenarios bare almost no resemblance. So forget watts.
Listen to the speakers. They will shown signs of distress if you push them too hard.
You'll be fine into one cab if, as others have said, you listen to the cab and turn it down if it distorts. A 50-watt difference isn't a big deal. Most of the time I run an amp that has 100-watt higher rating than the cab (800 into 700, 500 into 400). This actually gives a little more headroom for the transients (the cab can handle double its RMS rating for very short periods of time, like when you pop a note).
Most danger to cabinets derives from too much sub low content.
examples that may cause too much of this a cabinet savely can handle:
Bass knob turned full "open"
Compressor
distorting pedals or distorting the signal by (tube) preamp setting
Low tuning like F#0
Players damping technique of strings
The more of these "examples" come along just the same time then the more is (potential) danger to overload the speakers mechanical power handling.
examples that may cause too much of this a cabinet savely can handle:
Bass knob turned full "open"
Compressor
distorting pedals or distorting the signal by (tube) preamp setting
Low tuning like F#0
Players damping technique of strings
The more of these "examples" come along just the same time then the more is (potential) danger to overload the speakers mechanical power handling.
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